The present invention relates to radio communication systems. More particularly, and not by way of limitation, the present invention is directed to a system and method for adapting a broadcast service for different users under varying conditions.
A broadcast service transmits the same information to multiple users operating over a geographic area. In a cellular radio communication network, one or more base stations transmit the information to mobile users operating within the associated cell(s). In conventional broadcast services, the information is sent blindly, and it is hoped that the information is received. There is no feedback from the users, and there are no control mechanisms within the network to ensure that the broadcast information is received. To ensure that the broadcast information is received by as many users as possible, the information is broadcast with high transmit power, and repeaters may be utilized to simulcast information.
A disadvantage of the conventional approach is that a large amount of network resources are utilized by the broadcast service. In systems such as Direct Sequence Code Division Multiple Access (DS-CDMA) systems, the broadcast service may utilize a large amount of the avaible transmit power and channel codes, and may cause interference to other services. In Orthogonal Frequency Division Multiplexed (OFDM) systems, the broadcast service may utilize a large amount of the avaible transmit power and tone frequencies. What is needed in the art is a system and method for adapting a broadcast service for different users under varying conditions, that overcomes the deficiencies of conventional systems and methods.